The invention relates to activating mechanisms and particularly to activating mechanisms which function in response to some form of external actuation, e.g., the opening or closing of a window or door. As can be appreciated, such mechanisms are particularly applicable to alarm systems.
In U.S. Pat. No. 4,130,082 (A. C. Bouchard et al), there is described a multilamp flashlamp assembly which is capable of emitting both highly intense audible and visual signals when actuated by some external means, e.g. a door closing. In operation, the assembly's flashlamp component is triggered by a plurality of upwardly moving engagement members which release a corresponding plurality or prestressed striker springs. These springs in turn strike the projecting primer tubes of the assembly's percussive flashlamps to effect ignition thereof. The resulting high intensity flashes activate a series of hermetically-sealed conbustible members, e.g. pyrotechnics, located relative to the flashlamps to produce the desired audible ouputs. The highly intense noise emitted from the pyrotechnic may serve two purposes: (1) to scare away a prospective intruder; and (2) to trigger a suitable sound detector located within range of the pyrotechnic, which may then function to emit a continuous warning signal or perform additional, related functions. U.S. Pat. No. 4,130,082 is assigned to the assignee of the instant invention.
In U.S. Pat. No. 4,130,081 (R. G. Blaisdell et al) and 4,130,083 (A. C. Bouchard et al), both of which are also assigned to the assignee of this invention, there are described various embodiments of mechanisms which are capable of activating the assembly of U.S. Pat. No. 4,130,082 and which represent improvements over the activating mechanism described therein. The mechanism of U.S. Pat. No. 4,130,081 provides activation as a result of an increase in tension on a cord member projecting therefrom and secured to an engaging component, e.g. spherical ball, located within the mechanism's casing. The spherical ball mates with an angular surface on the mechanism's activator to force the activator upward when the aforedescribed tension increase occurs. A helical spring within the casing assures return of the activator subsequent to activation of the flashlamp article.
The mechanism of U.S. Pat. No. 4,130,083 operates differently from that of U.S. Pat. No. 4,130,081 in that the activator component is continuously biased upward and will thus rapidly move to effect article activation upon release thereof. Retention of the activator is provided by a pivotal arm which extends within the casing to engage said member. Activator disengagement and release occurs when an external surface, e.g. door, against which the pivotal arm was positioned moves away from the casing with the arm pivoting as a result thereof.
The present invention represents yet another improved means for activating flashlamp articles similar to those described in U.S. Pat. No. 4,130,082 and particularly is concerned with improving the devices defined in U.S. Pat. Nos. 4,130,081 and 4,130,083 providing safety means for preventing accidental activation thereof during periods of handling, installation, etc. Accidental ignition not only results in an unnecessary waste of material but also may prove inconvenient to the system's user in the event an accompanying detector is utilized in that it would be necessary for the user to reset the detector.
It is believed therefore that an improved activation means possessing the capability defined above would constitute a significant advancement in the art.